Absorbent article having elasticized bumpers

ABSTRACT

An absorbent article includes a moisture barrier, a bodyside liner bonded to the moisture barrier, and an absorbent structure disposed between the bodyside liner and moisture barrier. Elasticized bumpers which function as three-dimensional physical barriers to liquid movement are disposed in the margins of the article. The elasticized bumpers include an internal barrier structure and an elasticized cover disposed over the internal barrier structure and bonded to one of the margins. In particular embodiments, the elasticized cover is formed of a hydrophobic material, is unadhered to the internal barrier structure, and/or is comprised of elastic strands of variable degrees of power.

BACKGROUND OF THE INVENTION

The present invention relates to articles for containing and absorbingbody fluids. More particularly, the invention pertains to an absorbentarticle including elasticized bumpers that conform to the shape of thewearer and reduce the potential for side leakage.

Disposable absorbent articles such as diapers, training pants, femininecare products and adult incontinence products have been constructed inan effort to contain and absorb urine and other body exudates. Most ofthese absorbent articles include several common components.Specifically, disposable absorbent articles routinely include a liquidpermeable bodyside liner, a liquid impermeable backing sheet, and anabsorbent material disposed between the bodyside liner and the backingsheet. These products also include some form of attachment system,although the specific type may vary among fastening tapes, belts,garment adhesive, elastic straps, mechanical fasteners, integral sidepanels, or the like.

One common concern in designing the foregoing type of disposableabsorbent article is leakage, and in particular leakage of liquid fromthe side edges of the article. A wide variety of special components havebeen developed and added to absorbent articles in order to reduce theinstances of side leakage. For instance, many absorbent articles includeelastic structures positioned along the sides of the absorbent materialand stretch bonded to the bodyside liner and backing sheet. The elasticstructures are intended to gather the side portions of the article andform seals, gaskets or barriers to impede the flow of liquid past theside edges of the article. In addition to leg elastic structures,absorbent articles have also included elasticized containment flapswhich stand up from the surface of the bodyside liner, again in anattempt to control the movement of liquid as well as other body wastestoward the side edges of the article.

Despite the demonstrable improvement in containing body wastes, and inparticular urine, afforded by such elasticized structures, absorbentarticles are still subject to failures in the form of leakage past theirside edges. This may be due in part to the fact that individual elasticelements have been relied upon to provide a relatively high degree ofcontraction of the article. Consequently, the gatherable materials towhich the individual elastic elements are attached tend to form manyrugosities, such as wrinkles or creases along the length of the elasticelements when they are in a semi-relaxed state. These rugosities formedin the gatherable material by the individual elastic elements may form agreat number of relatively small leakage sites. Additionally, theserugosities tend to rub against the skin of the wearer during use and maycontribute to irritation or chafing.

Therefore, what is lacking and needed in the art is an improvedabsorbent article having elasticized structures that presentthree-dimensional physical barriers to liquid movement, and specificallyelasticized structures that reduce the instances of leakage from theside edges of the article by minimizing or eliminating the formation ofrugosities which may result in leakage sites and skin irritation.

SUMMARY OF THE INVENTION

In response to the discussed deficiencies in the prior art, a newdisposable absorbent article has been developed. The absorbent articleincludes elasticized bumpers positioned between an absorbent structureand side edges of the article. The components of the elasticized bumperare desirably selected to retard lateral movement of liquid away fromthe absorbent structure and minimize or eliminate the formation ofrugosities which could otherwise form leakage passageways toward theside edges of the article or cause skin irritation.

In one aspect, the invention concerns an absorbent article including amoisture barrier having longitudinal end edges and longitudinal sideedges extending between the end edges, a bodyside liner bonded to themoisture barrier, and an absorbent structure disposed between thebodyside liner and moisture barrier. The bodyside liner, the moisturebarrier, or both form opposite margins which extend beyond the absorbentstructure. An elasticized bumper of the absorbent article is disposed ineach of the margins. Each of the elasticized bumpers includes aninternal barrier structure formed of a resilient material bonded to oneof the margins. Each of the elasticized bumpers also includes anelasticized cover disposed over the internal barrier structure andbonded to one of the margins, with the elasticized cover being formed ofa hydrophobic material.

Another aspect of the invention concerns an absorbent article havingopposite margins and an elasticized bumper disposed in each of themargins. Each of the elasticized bumpers includes an internal barrierstructure bonded to one of the margins and an elasticized cover disposedover the internal barrier structure. Lateral portions of the elasticizedcover are bonded to one of the margins, however, the elasticized coveris unadhered to the internal barrier structure.

In another aspect, the invention concerns an absorbent article havingopposite margins and an elasticized bumper disposed in each of themargins. Each of the elasticized bumpers includes an internal barrierstructure bonded to one of the margins, and an elasticized coverdisposed over the internal barrier structure and bonded to one of themargins. The elasticized cover includes a casing layer and at least 4elastic strands operatively joined to the casing layer. The elasticstrands are arranged generally parallel to one another and within about8 millimeters of neighboring strands.

Numerous features and advantages of the present invention will appearfrom the following description. In the description, reference is made tothe accompanying drawings which illustrate preferred embodiments of theinvention. Such embodiments do not represent the full scope of theinvention. Reference should therefore be made to the claims herein forinterpreting the full scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 representatively shows a perspective view of a disposableabsorbent article according to the present invention.

FIG. 2 representatively shows a top plan view of several components ofthe disposable absorbent article shown in FIG. 1, in a flat andstretched condition and with portions broken away for purposes ofillustration.

FIG. 3 representatively shows an enlarged section view taken generallyfrom the plane of the line 3--3 in FIG. 2.

FIG. 4 representatively shows a schematic view illustrating a method ofmaking a disposable absorbent article such as that shown in FIGS. 1-3.

FIG. 5 representatively shows a top plan view of several components ofan alternative absorbent article according to the present invention.

FIG. 6 representatively shows an enlarged section view taken generallyfrom the plane of the line 6--6 in FIG. 5.

FIG. 7 is a top plan view of a template used in a Product Tension Test.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings:

(a) "Bonded" refers to the joining, adhering, connecting, attaching, orthe like, of two elements. Two elements will be considered to be bondedtogether when they are bonded directly to one another or indirectly toone another, such as when each is directly bonded to intermediateelements.

(b) "Disposable" includes being disposed of after use and not intendedto be washed and reused.

(c) "Disposed," "disposed on," "disposed with," "disposed at," "disposednear" and variations thereof are intended to mean that one element canbe integral with another element, or that one element can be a separatestructure bonded to or placed with or placed near another element.

(d) "Elastic," "elasticized" and "elasticity" mean that property of amaterial by virtue of which it tends to recover its original size andshape after removal of a force causing a deformation.

(e) "Elastomeric" refers to a material or composite which can beelongated by at least 25 percent of its relaxed length and which willrecover, upon release of the applied force, at least 10 percent of itselongation. It is generally preferred that the elastomeric material orcomposite be capable of being elongated by at least 100 percent, morepreferably by at least 200 percent, of its relaxed length and recover,upon release of an applied force, at least 50 percent of its elongation.

(f) "Extension," "extend" and "extended" mean the change in length of amaterial due to stretching, expressed in units of length.

(g) "Fabrics" is used to refer to all of the woven, knitted and nonwovenfibrous webs.

(h) "Flexible" refers to materials which are compliant and which willreadily conform to the general shape and contours of the wearer's body.

(i) "Force" includes a physical influence exerted by one body on anotherwhich produces acceleration of bodies that are free to move anddeformation of bodies that are not free to move.

(j) "Hydrophilic" describes fibers or the surfaces of fibers which arewetted by the aqueous liquids in contact with the fibers. The degree ofwetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90° are designated "wettable" orhydrophilic, while fibers having contact angles greater than 90° aredesignated "nonwettable" or hydrophobic.

(k) "Integral" is used to refer to various portions of a single unitaryelement rather than separate structures bonded to or placed with orplaced near one another.

(l) "Inward" and "outward" refer to positions relative to the center ofan absorbent garment, and particularly transversely and/orlongitudinally closer to or away from the longitudinal and transversecenter of the absorbent garment.

(m) "Layer" when used in the singular can have the dual meaning of asingle element or a plurality of elements.

(n) "Liquid impermeable" when used to describe a layer or laminate meansthat liquid such as urine will not pass through the layer or laminateunder ordinary use conditions in a direction generally perpendicular tothe plane of the layer or laminate at the point of liquid contact.

(o) "Member" when used in the singular can have the dual meaning of asingle element or a plurality of elements.

(p) "Nonwoven web" means a web of material which is formed without theaid of a textile weaving or knitting process.

(q) "Operatively joined" and "operatively connected," with reference tothe attachment of an elastic member to another element, means that theelastic member when attached to or connected to the element, or treatedwith heat or chemicals, by stretching, or the like, gives the elementelastic properties; and with reference to the attachment of anon-elastic member to another element, means that the member and elementcan be attached in any suitable manner that permits or allows them toperform the intended or described function of the joinder. The joining,attaching, connecting or the like can be either directly, such asjoining either member directly to an element, or can be indirectly bymeans of another member disposed between the first member and the firstelement.

(r) "Stretch bonded" refers to an elastic member being bonded to anothermember while the elastic member is extended at least about 25 percent ofits relaxed length. Desirably, the term "stretch bonded" refers to thesituation wherein the elastic member is extended at least about 100percent, and more desirably at least about 200 percent, of its relaxedlength when it is bonded to the other member.

(s) "Stretch bonded laminate" refers to a composite material having atleast two layers in which one layer is a gatherable layer and the otherlayer is an elastic layer. The layers are joined together when theelastic layer is in an extended condition so that upon relaxing thelayers, the gatherable layer is gathered.

(t) "Unadhered" refers to an absence of bonds of sufficient strength towithstand the forces typically encountered during ordinary wearing ofthe diaper.

These terms may be defined with additional language in the remainingportion of the specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1-3, an absorbent article formed according tothe invention is shown for purposes of illustration as a disposableundergarment 20 for adult incontinence. The invention may also beembodied in other types of garments, such as other adult incontinencearticles, diapers, feminine care products, training pants, reusableabsorbent articles, underwear, bathing suits, other personal care orhealth care garments, or the like.

In general, the undergarment 20 includes elasticized bumpers 60 disposedin each of the side margins 38 of the undergarment. In one embodiment,each elasticized bumper 60 includes an internal barrier structure 62bonded to the side margin 38 and an elasticized cover 64 disposed overthe internal barrier structure. In one aspect of the invention, thecover 64 is formed of a hydrophobic material to retard the spread ofliquid toward the side edges 28 and 29 of the undergarment 20. Inanother aspect of the invention, the elasticized cover 64 includeslateral portions 74 that are bonded to the side margins 38, leaving theelasticized cover not directly adhered to the internal barrier structure62. This permits the elasticized cover 64 to move relative to theinternal barrier structure 62 and decreases the formation of largerugosities which would otherwise be caused by gathering of the internalbarrier structure. In yet another aspect of the invention, theelasticized cover 64 includes at least one casing layer 65 and at least4 elastic strands 66 operatively joined to the casing layer. The elasticstrands 66 are arranged generally parallel to one another and withinabout 8 millimeters of neighboring strands to improve uniform gatheringof the cover 64 and again minimize the formation of rugosities. In analternative embodiment, an elasticized bumper 202 includes anelasticized cover 64 that fully encircles the internal barrier structure62.

The illustrated undergarment 20 defines a longitudinal axis or centerline and a transverse axis or center line, represented by arrows 22 and24 in FIG. 2. The undergarment 20 has opposite, front and backlongitudinal end edges 26 and 27, and first and second longitudinal sideedges 28 and 29 that extend between the longitudinal end edges. Theundergarment 20 includes a first or front waist region 30, a second orback waist region 32, and an intermediate, crotch region 34 positionedbetween and interconnecting the front and back waist regions. The outeredges of the undergarment 20 define a periphery 36 in which thelongitudinally extending side margins are designated 38 and thelaterally extending end margins are designated 39. The end edges 26 and27 and side edges 28 and 29 are shown as generally straight, butoptionally, may be curvilinear and contoured.

The front waist region 30 is contiguous with the front end edge 26 andextends longitudinally inward therefrom toward the transverse centerline 24 of the undergarment 20. The back waist region 32 is contiguouswith the back end edge 27 and extends longitudinally inward therefromtoward the transverse center line 24. The waist regions 30 and 32comprise those upper portions of undergarment 20 which, when worn,wholly or partially cover or encircle the waist or mid-lower torso ofthe wearer. The intermediate, crotch region 34 comprises that portion ofundergarment 20 which, when worn, is positioned between the legs of thewearer and covers the lower torso of the wearer. Thus, the crotch region34 is the area where insults of urine typically occur in theundergarment or other disposable absorbent article.

The undergarment 20 includes a substantially liquid impermeable moisturebarrier 40, an absorbent structure 42 (FIGS. 2 and 3) disposed on themoisture barrier, and a substantially liquid permeable bodyside liner 44bonded to the moisture barrier to sandwich the absorbent structuretherebetween. The moisture barrier 40 and bodyside liner 44 aredesirably longer and wider than the absorbent structure 42 so that theperipheries of the moisture barrier and bodyside liner may be bondedtogether using ultrasonic bonds, thermal bonds, adhesives, or othersuitable means. The periphery of the moisture barrier 40, the bodysideliner 44, or the peripheries of both, typically form the side and endmargins 38 and 39 of the undergarment 20. The absorbent structure 42 mayalso be bonded to the moisture barrier 40 and/or the bodyside liner 44using ultrasonic bonds, thermal bonds, adhesives, or other suitablemeans.

The moisture barrier 40 desirably comprises a material that is formed ortreated to be liquid impermeable. Alternatively, the moisture barrier 40may comprise a liquid permeable material and other suitable means (notshown), such as a liquid impermeable layer associated with the absorbentstructure 42, may be provided to impede liquid movement away from theabsorbent structure. The moisture barrier 40 may also be gas permeable,such that gases encountered during use of the absorbent article are ableto pass through the material under ordinary use conditions, over eitherall or part of its surface area.

The moisture barrier 40 may comprise a single layer of material or alaminate of two or more separate layers of material. Suitable moisturebarrier materials include films, wovens, nonwovens, laminates of films,wovens, and/or nonwovens, or the like. For example, the moisture barrier40 may comprise a thin, substantially liquid impermeable web or sheet ofplastic film such as polyethylene, polypropylene, polyvinyl chloride orsimilar material. The moisture barrier material may be transparent oropaque and have an embossed or matte surface. One particular materialfor the moisture barrier 40 is a polyethylene film that has a nominalthickness of about 0.025 millimeter and a systematic matte embossedpattern, and that has been corona treated on both sides. Anothersuitable moisture barrier material is an adhesive or thermal laminatecomprising a cast or blown film formed of polypropylene, polyethylene orthe like, and a spunbond web formed of polypropylene and polyethylenemedium-crimped bicomponent fibers in a 50/50 side-by-side configuration.

The absorbent structure 42 comprises materials adapted to absorb andretain liquid waste. The absorbent structure 42 may comprise variousabsorbent materials, such as an air-formed batt of cellulosic fiberssuch as wood pulp fluff or a coform material composed of a mixture ofcellulosic fibers and synthetic polymer fibers. Polymer fibers may beincorporated, for example, in the manner described in U.S. Pat. No.5,227,107 issued Jul. 13, 1993, to Dickenson et al. The absorbentstructure 42 may also include compounds to increase its absorbency, suchas 0-95 weight percent of organic or inorganic high-absorbencymaterials, which are typically capable of absorbing at least about 15and desirably more than 25 times their weight in water. Suitablehigh-absorbency materials are described in U.S. Pat. Nos. 4,699,823issued Oct. 13, 1987, to Kellenberger et al. and 5,147,343 issued Sep.15, 1992, to Kellenberger, which are incorporated herein by reference.High-absorbency materials are available from various commercial vendors,such as Dow Chemical Company, Hoechst Celanese Corporation, and AlliedColloids, Inc. The absorbent structure 42 may also include tissue layersor acquisition or distribution layers to help maintain the integrity offibrous absorbents or transport liquids (not shown).

In the illustrated embodiment, the moisture barrier 40 extends the fulllength and width of the undergarment 20 and thus defines in part thefront and back end edges 26 and 27 and the first and second side edges28 and 29. As best shown in FIG. 2, the absorbent structure 42 hasopposite end edges 45 and opposite side edges 46 that extend between theend edges. The end and side edges 45 and 46 of the absorbent structure42 are desirably spaced inward from the end edges 26 and 27 and sideedges 28 and 29 of the undergarment 20. In the longitudinal direction,for example, the absorbent structure 42 desirably has a length of fromabout 50 to about 95 percent of the undergarment 20. The bodyside liner44 also includes opposite end edges 48 and opposite side edges 49 thatextend between the end edges. In the illustrated embodiment, the endedges 48 extend to the full length of the undergarment 20, although theside edges 49 are spaced inward from the side edges 28 and 29 of theundergarment. Alternatively, of course, the side edges 49 of thebodyside liner 44 could extend to or independently form the side edges28 and 29 of the undergarment 20.

As best shown in FIG. 3, the undergarment 20 desirably includes acarrier sheet 50 disposed between the absorbent structure 42 and themoisture barrier 40. The carrier sheet 50 may serve as a carrier web forthe absorbent structure 42 during high speed manufacturing processes tomanufacture the undergarment 20. The carrier sheet 50 desirablycomprises a hydrophilic, air and liquid permeable material such as ahigh wet strength tissue. For example, the carrier sheet 50 may comprisea 17 grams per square meter (gsm) web of cellulose fibers.Alternatively, the carrier sheet 50 may comprise nonwettable nonwovenwebs formed of polyolefins, polyesters, rayon or the like, desirablywith relatively low basis weights, such as less than about 30 gsm, andwith sufficient mechanical strength to withstand handling in ahigh-speed manufacturing process, a film, or the like. The carrier sheet50 has opposite end edges 51 and opposite side edges 52 that extendbetween the end edges. The end edges 51 of the carrier sheet 50 may becoextensive with the end edges 45 of the absorbent structure 42. Thewidth of the carrier sheet 50 is desirably such that the side edges 52extend transversely outward of the absorbent structure 42 into the sidemargins 38 of the undergarment 20.

The illustrated undergarment 20 also includes a liquid handling layer 54that is disposed between the bodyside liner 44 and the absorbentstructure 42. The liquid handling layer 54 has opposite end edges 55 andopposite side edges 56 that extend between the end edges. Desirably, butnot necessarily, the length of the liquid handling layer 54 is such thatthe end edges 55 are coextensive with the end edges 26 and 27 of theundergarment 20. Thus, the liquid handling layer 54 is positioned in thefront and back waist sections 30 and 32 between the absorbent structure42 and the end edges 26 and 27 of the undergarment 20. The width of theliquid handling layer 54 is suitably such that the side edges 56 arepositioned between the side edges 46 of the absorbent structure 42 andthe side edges 28 and 29 of the undergarment 20.

The liquid handling layer 54 is desirably present in the front and backwaist sections 30 and 32 to draw liquid that may be present in thoseregions away from the interior surface of the undergarment 20 and thusaway from the skin of a wearer. The liquid handling layer 54 maycomprise an absorbent material such as one or more cellulose tissuesheets or an airlaid web of hydrophilic fibers. Alternatively, theliquid handling layer 54 may comprise a material adapted to rapidly takein and/or distribute liquids. Any woven or nonwoven web adapted toquickly take in and/or transport liquids may be suitable for the liquidhandling layer 54. For example, the liquid handling layer 54 maycomprise a nonwoven web such as a spunbonded, meltblown or bonded-cardedweb composed of synthetic polymer filaments or fibers such aspolypropylene, polyethylene, polyesters or the like or a web of naturalpolymer filaments or fibers as rayon or cotton. The liquid handlinglayer 54 desirably comprises a material that is formed or treated to besubstantially hydrophilic. Examples of suitable materials are alsodescribed in U.S. Pat. No. 5,192,606 issued Mar. 9, 1993, to D. Proxmireet al.; U.S. Pat. No. 4,798,603 issued Jan. 17, 1989, to S. Meyer etal.; U.S. Pat. No. 5,364,382 issued Nov. 15, 1994, to M. Latimer et al.;U.S. patent application Ser. No. 757,760 of W. Hanson et al. filed Sep.11, 1991 (Attorney docket No. 9922); U.S. patent application Ser. No.206,986 of C. Ellis and D. Bishop, entitled FIBROUS NONWOVEN WEB SURGELAYER FOR PERSONAL CARE ABSORBENT ARTICLES AND THE LIKE, and filed Mar.4, 1994 (Attorney docket No. 11,256); and U.S. patent application Ser.No. 206,069 of C. Ellis and R. Everett, entitled IMPROVED SURGEMANAGEMENT FIBROUS NONWOVEN WEB FOR PERSONAL CARE ABSORBENT ARTICLES ANDTHE LIKE, and filed Mar. 4, 1994 (Attorney docket No. 11,387); thedisclosures of which are hereby incorporated by reference.

In the illustrated embodiment, the carrier sheet 50 is disposed betweenthe moisture barrier 40 and the absorbent structure 42. Alternatively,the carrier sheet 50 may be disposed between the absorbent structure 42and the bodyside liner 44. In such case, the carrier sheet 50 should beliquid permeable and may function as the liquid handling layer 54.Further, the liquid handling layer 54 may be disposed between theabsorbent structure 42 and the moisture barrier 40.

The bodyside liner 44 is formed of a liquid permeable material so thatliquid waste, and possibly semi-solid waste as well, can pass throughthe liner and be absorbed by the absorbent structure 42. Suitablebodyside liners 44 may comprise a nonwoven web or sheet of wet strengthtissue paper, a spunbonded, meltblown or bonded-carded web composed ofsynthetic polymer filaments or fibers, such as polypropylene,polyethylene, polyesters or the like, or a web of natural polymerfilaments or fibers such as rayon or cotton. In addition, the bodysideliner 44 is desirably nonelastic and may be treated with a surfactant toaid in liquid transfer. In a particular embodiment of the invention, theliner 44 comprises a nonwoven, spunbond polypropylene fabric composed ofabout 2.8-3.2 denier fibers formed into a web having a basis weight ofabout 22 gsm and density of about 0.06 gm/cc. The fabric is surfacetreated with about 0.28 weight percent of a surfactant commerciallyavailable from Union Carbide Chemicals and Plastics Company, Inc., ofDanbury, Conn., U.S.A. under the trade designation Triton X-102.

The undergarment 20, portions of which are in a stretched and laid flatcondition in FIG. 2, is illustrated as having a rectangular periphery36. Of course, the undergarment 20 may optionally be hourglass-shaped,I-shaped, T-shaped, or irregularly-shaped. The general shape of theabsorbent structure 42 may correspond to the shape of the undergarment20 or assume a different shape.

To conform the side margins 38 of the undergarment 20 to the body of thewearer and minimize the likelihood of leakage from the side edges 28 and29, the undergarment is provided with an elasticized bumper 60 in eachside margin 38. The elasticized bumpers 60 are disposed on the moisturebarrier 40 at least in the crotch region 34, but they may also extendinto the front and back waist regions 30 and 32. The elasticized bumpers60 may be generally straight or curved and may but need not follow theperipheral shape of either the side edges 46 of the absorbent structure42 or the side edges 28 and 29 of the undergarment 20. In onealternative embodiment, the elasticized bumpers 60 may be positioned inone or both of the waist regions 30 and 32, such as in end margins 39,oriented parallel to the transverse axis 24 instead of or in addition tobeing positioned along the side edges 28 and 29 (not shown).

In the embodiment shown in FIGS. 1-3, the elasticized bumpers 60comprise an internal barrier structure 62 disposed on the moisturebarrier 40 and a cover 64 disposed over the internal barrier structure.The illustrated cover 64 includes a pair of casing layers 65 and aplurality of strands 66 of elastic positioned between and operativelyjoined to the casing layers (FIG. 3). Alternatively, the cover 64 maycomprise a single elastomeric fabric or a composite of a single casinglayer and one or more elastomeric elements or layers (not shown).

The internal barrier structures 62 of the undergarment 20 shown in FIGS.1-3 are oriented parallel to the longitudinal axis 22 and positionedbetween the side edges 46 of the absorbent structure 42 and the sideedges 28 and 29 of the undergarment. In particular, the internal barrierstructures 62 are suitably spaced from the side edges 46 of theabsorbent structure 42 by from 0 to about 7 centimeters (cm), andparticularly from about 0.5 to about 3 cm. Also, the internal barrierstructures 62 are suitably positioned from about 0.5 to about 4 cm fromthe side edges 28 and 29, such as from about 1 to about 3 cm from theside edges. The length of the internal barrier structures 62 is suitablycomparable to the length of the crotch region 34 but may be up to thefull length of the undergarment 20. For convenience of manufacturingthough, as discussed in greater detail below, the length of the internalbarrier structures 62 is desirably the same as the length of theabsorbent structure 42.

In the illustrated embodiment, the internal barrier structures 62 arepositioned transversely inward from the side edges 52 of the carriersheet 50. A bead 68 of adhesive or other suitable means is used to bondthe internal barrier structures 62 to the carrier sheet 50 (FIG. 3). Theadhesive bead 68 may also be effective to penetrate through the carriersheet 50 and bond the carrier sheet to the moisture barrier 40.Desirably, the adhesive bead 68 is continuous along the length of theinternal barrier structure 62 and does not allow liquid to penetratebetween the internal barrier structure and the moisture barrier 40.

The internal barrier structures 62 desirably function to elevate theelasticized bumpers 60 from the plane of the undergarment 20 defined bythe longitudinal and transverse axes 22 and 24. In particular, theelasticized bumpers 60 suitably have a height dimension measured fromthe plane of the moisture barrier 40 of from about 3 to about 25millimeters (mm), and particularly from about 5 to about 15 mm. Thewidth of the elasticized bumpers 60 is desirably from about 2 to about30 mm, and more particularly, from about 5 to about 15 mm, for improvedperformance.

The internal barrier structures 62 may be formed of any material whichallows the elasticized bumpers 62 to conform to the shape of the wearer.In one particular embodiment, the internal barrier structures 62comprise a resilient sliver structure formed of 100 percent 2.2 denierhydrophobic polypropylene staple fibers having a length of 3.8 cm andavailable from Hercules Inc. of Wilmington, Del., U.S.A., under thetrade designation T190. The term "sliver" refers generally to acontinuous untwisted strand or bundle of flat fibers produced by aconventional carding process. Carding separates fibers from each other,lays them parallel, forms them into a thin web, and then condenses theminto the sliver. The process for forming the sliver structure isdisclosed in U.S. Pat. No. 5,133,371 issued Jul. 28, 1992, to Sivess,which is incorporated herein by reference.

The sliver structure may be composed of a wide variety of cardablefibers, but is desirably comprised of those fibers which aresubstantially nonabsorbent, nonelastomeric and hydrophobic in nature.The internal barrier structures 62 may also be hydrophilic, particularlyin instances where the cover 64 is formed or treated to be hydrophobic.The internal barrier structures 62 may comprise additional components toenhance the resiliency of the structures, such as foams or resilientfibers. Ends 69 of the side barrier structures 62 are desirably but notnecessarily coextensive with the ends 51 of carrier sheet 50 and theends 45 of the absorbent structure 42.

The cover 64 is formed of an elastomeric material or composite adaptedto gather the side margins 38 of the undergarment 20 and maintain theelasticized bumpers 60 against the skin of the wearer. The cover 64includes opposite longitudinal ends 70 and opposite longitudinal sides71 extending between the ends. The ends 70 of the cover 64 in theillustrated embodiment are coextensive with the end edges 26 and 27 ofthe undergarment 20, and one side edge 71 of each cover 64 is desirablycoextensive with or adjacent to a side edge 28 or 29 of theundergarment.

With particular reference to FIG. 3, the covers 64 also include oppositelateral portions 74 with a central portion 75 positioned between andinterconnecting the lateral portions. The lateral portions 74 arecontiguous with the side edges 71 of the covers 64. The covers 64 aredisposed on the internal barrier structures 62 and have sufficient widthsuch that the lateral portions 74 can be bonded to the moisture barrier40 with beads 72 of adhesive or other suitable means. As illustrated,the adhesive beads 72 nearest the side edges 28 and 29 directly bond thecovers 64 to the moisture barrier 40, while the adhesive beads 72nearest the absorbent structure 42 directly bond the covers 64 to thecarrier sheet 50 and are desirably effective to penetrate through thecarrier sheet and bond the carrier sheet to the moisture barrier. Bothadhesive beads 72 are desirably continuous along the length of thecovers 64 and do not allow liquid to penetrate between the covers andthe moisture barrier 40. Notably, the central portions 75 of the covers64 are desirably not bonded directly to the internal barrier structures62. Rather, the inner surfaces of the covers 64 are free to slide overthe exterior surfaces of the internal barrier structure 62 to minimizethe formation of rugosities.

The casing layers 65 desirably define the end and side edges 70 and 71of the cover 64. The casing layers 65 may be formed of any flexible,gatherable material. In particular embodiments, the casing layers 65 areeither impermeable to liquids or formed or treated to be hydrophobic.Less desirably, the casing layers 65 may be hydrophilic or liquidpermeable and the internal barrier structures 62 are formed of ahydrophobic material. One particular material that may be useful informing the casing layer 65 is a thermally point bonded web ofbicomponent spunbond fibers having a basis weight of from about 10 toabout 27 gsm (0.3-0.8 osy), such as from about 12 to about 20 gsm(0.4-0.6). The fibers are 50/50 side-by-side polypropylene/polyethylenebicomponent fibers constructed of polyethylene available from DowChemical Company of Midland, Mich., U.S.A., under the trade designationASPUN™ 6811A and polypropylene available from Exxon Chemical Company ofHouston, Tex., U.S.A., under the trade designation PP3445. The extrudedfibers suitably have an average fiber diameter of between about 17 and25 microns, such as about 23 microns, and a low crimp, such asapproximately one or fewer crimps per extended inch using ASTM testmethod D-3937-82. The web may be produced according to the processes forproduction of bicomponent webs as described in U.S. Pat. No. 5,382,400issued Jan. 17, 1995, to Pike et al., the disclosure of which isincorporated herein by reference. Other suitable materials for use asthe casing layer 65 include copolymer, polypropylene, polyester or nylonspunbonds, combinations of these polymers in bicomponent constructionsor in blends, and carded webs composed of suitable cardable fibers. Thefibers may have varying degrees of crimp; however, the crimp isdesirably less than approximately 15 or fewer crimps per extended inch.Also, the webs may be bonded by other suitable means such as through airbonding.

The cover 64 may alternatively comprise only a single casing layer 65with the elastic strands 66 bonded to the single casing layer on thesurface facing the internal barrier structure 62. Still alternatively,the cover 64 may be composed of a substantially elastomeric layer, suchas polymer films, woven fabrics, nonwoven fabrics or the like, as wellas combinations thereof, rather than a plurality of strands ofelastomeric material. For example, the cover 64 can be composed of astretch-bonded-laminate (SBL) material, a neck-bonded-laminate (NBL)material, an elastomeric film, an elastomeric foam material, or thelike. For example, suitable meltblown elastomeric fibrous webs forforming the cover 64 are described in U.S. Pat. No. 4,663,220 issued May5, 1987 to T. Wisneski et al., the disclosure of which is herebyincorporated by reference. Examples of composite fabrics comprising atleast one layer of nonwoven textile fabric secured to a fibrous elasticlayer are described in European Patent Application EP No. 0 110 010published on Apr. 8, 1987 with the inventors listed as J. Taylor et al.,the disclosure of which is hereby incorporated by reference. Examples ofNBL materials are described in U.S. Pat. No. 5,226,992 issued Jul. 13,1993 to Morman; U.S. Pat. No. 5,336,545 issued Aug. 9, 1994 to Morman;and U.S. patent application Ser. No. 08/276,924 by Haffner et al., filedJul. 19, 1994, and titled "COMPOSITE ELASTIC NECK-BONDED MATERIAL"(Attorney Docket No. 8704.4); the disclosures of which are herebyincorporated by reference.

In the illustrated embodiment, elastic strands 66 are disposed betweenthe casing layers 65 and operatively joined thereto using adhesives orother suitable means (FIG. 3). For example, the elastic strands 66 maybe adhesively bonded to the casing layers 65 using a 5 gsm applicationof a hot melt, rubber-based adhesive available from Findley Adhesives ofWauwatosa, Wis., U.S.A., under the trade designation H-2096. Theelastomeric component of the adhesive is available from the ShellChemical Company of Houston, Tex., U.S.A., under the trade designationKRATON. The elastic strands 66 may be formed of a dry-spun coalescedmulti-filament elastomeric thread sold under the trade name LYCRA® andavailable from E.I. Du Pont de Nemours and Company. Alternatively, theelastic component of the cover 64 may comprise other typical elasticsutilized in the undergarment-making art, such as a thin ribbon ofnatural or synthetic rubber, a stretch bonded laminate material, otherstrand structures such as isoprene strands available from JPSElastomerics, Stuart, Va., U.S.A., elastomeric films such as EVA orurethane films, hot melt elastomeric adhesives, or the like.

The number, spacing, positioning, power and overall tension of theelastic strands 66 are desirably controlled to maintain the elasticizedbumpers 60 against the body of the wearer and create a physical barrierto lateral liquid flow, while at the same time minimizing the formationof rugosities which could create leakage sites. In particularembodiments, the covers 64 comprise at least 4 elastic strands 66, andparticularly from 4 to 12 elastic strands, and more particularly from 6to 8 elastic strands. The elastic strands 66 are spaced from neighboringstrands by less than about 8 mm, and particularly by from about 3 toabout 6 mm from neighboring strands for improved performance. Theelastic strands 66 are suitably spaced from the adhesive beads 72 so theelastic characteristics of the strands are not defeated. The individualelastic strands 66 may be identical to one another. Alternatively,however, at least one of the elastic strands 66 has greater elasticpower than at least one of the other elastic strands 66. Further, theelastic strands 66 having greater elastic power are desirably located ontop of the interior barrier structures 62, which corresponds to thecentral portion 75 of the cover 64. In the illustrated embodiment (FIG.3), for example, the cover 64 includes 7 elastic strands 66, and 3 ofthose strands desirably have greater elastic power than the remaining 4strands. The 3 strands of greater elastic power are desirably centrallylocated between the adhesive beads 72 that bond the cover 64 to the sidemargins 38. This configuration has the benefit of positioning theelastic strands 66 with greater elastic power closer to the body of thewearer. As a result, the undergarment 200 tends to more easily assume a"U" shape as viewed in the longitudinal direction 22. The "U" shape isbest suited to conform to the body of the wearer and aid in formation ofa leakage barrier.

The term elastic power is used herein to mean the retraction force ofone elastic member compared to the retraction force of another elasticmember. One elastic member may have more elastic power than anothermember due to the nature of the materials of which they are made, thelevels of elongation of the elastic members, the decitex of elasticmembers, or the like. By way of illustration, a cover 64 may incorporateone set of elastic strands 66 having a decitex of 620 and another set ofelastic strands having a decitex of 940. Both sets of strands may bestretched to 270 percent elongation and bonded to the casing layer 65.The set of 940 decitex strands could be positioned in the centralportion 75 of the cover 64 and the set of 620 decitex strands could bepositioned in the lateral portions 74 of the cover.

The elasticized bumpers 60 of the present invention desirably providerelatively high degrees of tension without creating localized regions ofhigh tension that contribute to skin irritation. In particular, the sidemargins 38 of the undergarment 20 desirably possess a side margintension of from about 0.06 to about 0.30 kilograms. One suitableprocedure for determining the side margin tension of an absorbentarticle is the Product Tension Test set forth in the Test Methodssection below.

The attachment system in the illustrated embodiment includes a pair ofstrap members 80 and fastening components to releasably attach the strapmembers to the front and back waist regions 30 and 32 (FIG. 1). Thefastening components include a retainer 82 in the form of a buttonbonded at each end of each strap member 80. The retainers 82 may bereleasably secured in slits 84 formed near the corners of theundergarment 20 in the moisture barrier 40 and other components. Whenthe undergarment 20 is positioned on the wearer, the straps 80 extendbetween the front and back slits 84 so that the retainers 82 may bereleasably secured in the slits. Optionally, other types of attachmentsystems, such as tapes, stretchable side panels, self-engaging geometricshaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads,balls on stems, or the like, may be employed. The illustrated attachmentsystem as well as alternatives thereto are described in U.S. Pat. No.4,315,508 issued Feb. 16, 1982, to Bolick and U.S. Pat. No. 5,386,595issued Feb. 7, 1995, to Kuen et al., the disclosures of which areincorporated herein by reference.

The strap members 80 (FIG. 1) are each generally rectangular strips ofmaterial, which material is desirably an elastic material capable ofstretching to approximately 2.8 to 3 times its relaxed length. The strapmembers 80 desirably have a length from about 15 to about 41 centimeters(cm.), and a width from about 1 to about 5 cm. For example, each strapmember 80 may be 28 cm. long and 2.5 cm. wide. The cut ends of the strapmembers 80 may be bonded by ultrasonics, adhesives or other suitablemeans to prevent raveling.

In use, the undergarment 20 is positioned on the wearer and secured withthe attachment system. The function of the elasticized bumpers 60includes both gathering the undergarment 20 in the longitudinaldirection 22 to conform the garment to the body as well as presenting araised physical barrier to impede the lateral movement of liquids. Inthis regard, the elasticized bumpers 60 and in particular the covers 64are formed of materials that resist liquid movement in the transversedirection. In particular embodiments, the covers 64 are desirablyunadhered to the underlying internal barrier structures 62 to minimizethe formation of large rugosities along the length of the elasticizedbumpers. Also in particular embodiments, the elasticized bumpers 60 areconstructed of individual elastic strands 66 and the number and spacingof the strands is selected so as to minimize the formation of smallrugosities along the surface of the elasticized bumpers. Both large andsmall rugosities would otherwise create sites where liquid could escapepast an elasticized physical barrier.

A particularly efficient method for constructing the undergarment 20described in relation to FIGS. 1-3 is schematically illustrated in FIG.4. The method includes a number of continuous processes and does notinvolve any cut-and-place operations. In particular, the method includesproviding a continuous carrier tissue web 100 from a forming or unwindsource 101, and providing a continuous absorbent web 102 from anabsorbent web source. For example, the absorbent web 102 may be suppliedfrom a forming drum 104, as is well known in the art. The absorbent web102 is disposed on the carrier web 100 and both are advanced in thedirection of arrow 106 via transport means 108, such as a beltedconveyor system or other suitable means. The absorbent web 102 isdesirably narrower than the carrier web 100 and centered between theside edges 52 (FIGS. 2 and 3) of the carrier web.

The carrier and absorbent webs 100 and 102 are routed past adhesivestation 110 where beads 68 of adhesive are applied to the carrier weboutward of the side edges 46 (FIGS. 2 and 3) of the absorbent web. Thecarrier and absorbent webs 100 and 102 continue to be advanced in thedirection of arrow 106 via transport means 112. A pair of continuousstrands 114 of material for forming the internal barrier structures 62of the undergarment 20 are provided from a forming or unwind source 115.The strands 114 of internal barrier material are routed past roller 116and united with the carrier web 100 at the location of the adhesivebeads 68 such that the strands 114 are bonded to the carrier web outwardof the side edges 46 of the absorbent web 102.

The continuous carrier web 100, the continuous absorbent web 102, andthe continuous strands 114 of internal barrier material together form acontinuous in-process composite structure 120, which is transported toan optional de-bulking unit 122 which functions to shape the absorbentweb 102. It will be apparent that the continuous strands 114 of internalbarrier material may be bonded to the continuous carrier web 100 eitherprior to or after the de-bulking unit 122.

The composite structure 120 is then conveyed by transport means 126 to aweb cutting mechanism 128, shown for purposes of illustration as arotating shear. The cutting mechanism 128 transversely cuts thecontinuous composite structure 120 into individual, in-process compositestructures 130. Each composite structure 130 comprises a carrier sheet50, an absorbent structure 42, and a pair of internal barrier structures62 (FIGS. 2 and 3). The carrier sheet 50 has opposite end edges 51 andopposite side edges 52. The absorbent structure 42 has opposite endedges 45 coterminous with end edges 51 of the carrier sheet 50 andopposite side edges 46 spaced inward from the side edges 52 of thecarrier sheet. The internal barrier structures 62 are positioned betweenthe side edges 46 of the absorbent structure 42 and the side edges 52 ofthe carrier sheet 50 and have opposite ends 69 coterminous with the endedges 51 of the carrier sheet. The individual composite structures 130exit the cutting mechanism 128 onto transport means 132 which istravelling at a speed greater than that of transport means 126. As aresult, the individual composite structures 130 become spaced from oneanother.

A continuous web 140 of moisture barrier material is provided from aforming or unwind source 142 and transported in the direction of arrow144. Adhesive beads 72 are provided from an adhesive source 146 anddisposed on the continuous moisture barrier web 140. Traditional legelastics may also be bonded to the moisture barrier web 140 if desired(not shown). The moisture barrier web 140 is routed past roll 148 to anassembly station 149.

Simultaneously, a continuous web 150 of bodyside liner material isprovided from a forming or unwind source 152 and transported in thedirection of arrow 154. Adhesive 156 may optionally be applied to thecontinuous bodyside liner web 150 from an adhesive source 158. Acontinuous web 160 of a liquid handling material is provided from aforming or unwind source 162, routed over transport roll 164 and unitedwith the continuous bodyside liner web 150 at another transport roll166. The combined bodyside liner web 150 and liquid handling web 160continue to be transported in the direction of arrow 154 past transportroll 168.

Two covers 64 are constructed and disposed over the internal barrierstructures 62, although the method and apparatus for forming only one ofthe covers appears in FIG. 4. Each cover 64 may be constructed from apair of continuous casing webs 170 and 172 provided from forming orunwind sources 174 and 176. Elastic strands 66 are provided from anelastic forming or unwind source 178 and operatively joined to thecasing webs 170 and 172 with adhesive 180 from an adhesive source 182.The adhesive 180 may be applied over the elongated elastic strands 66just prior to the strands coming into contact with one of the casingwebs 170, as disclosed in U.S. Pat. No. 4,842,666 issued Jun. 27, 1989,to Werenicz. The adhesive 180 is desirably applied intermittently andtimed to bond the elastic strands 66 to the casing webs 170 and 172 atlocations corresponding to the position of the internal barrierstructures 62. Alternatively, the adhesive 180 may be appliedcontinuously to the cover 64, or applied continuously and diverted overa portion of the length of the cover using a diverting mechanism such asthe air diverting system disclosed in U.S. Pat. No. 4,711,683 issuedDec. 8, 1987, to Merkatoris.

The casing webs 170 and 172 with the elastic strands 66 bonded theretoare then routed past a transport roll 184 and united with the bodysideliner web 150 and the liquid handling web 160, and all of thesecomponents are transported to the assembly station 149. It will beapparent that the components can be arranged so that the covers 64 areat least partially on top of the bodyside liner web 50 as illustrated,or alternatively positioned beneath the bodyside liner web (not shown).

The components of the undergarment 20 are united and bonded together atthe assembly station 149. The individual composite structures 130 areintroduced between the moisture barrier web 140 and the bodyside linerweb 150. The position of the covers 64 is controlled to coincide withthe position of the internal barrier structures 62. The elastic strands66 may be disposed directly over the internal barrier structures 62.Alternatively, however, the position of the covers 64 and/or the elasticstrands 66 may be controlled to concentrate the elastic strands eithertransversely inward or transversely outward of the internal barrierstructures 62. The adhesive beads 72 function to bond the covers 64 tothe moisture barrier, and other construction adhesives (not shown) maybe used to bond other components together.

From the assembly station 149, the components are carried by a transportmeans 186 to a cutting mechanism 188 which transversely cuts thecontinuous components to form individual undergarments 20. The cuttingmechanism 188, for example a rotary shear, is timed to cut between theindividual composite structures 130 and thus sever the moisture barrierweb 140, the bodyside liner web 150, the liquid handling web 160, thecasing webs 170 and 172, and the elastic strands 66. Desirably, thecutting mechanism 188 severs the covers 64 at locations where theadhesive 180 has been interrupted or diverted and does not bond theelastic strands 66 to the casing layers 65. As a result, the portions ofthe elastic strands 66 adjacent the ends 26 and 27 of the undergarment20 are free to snap back to the location of the adhesive 180, such asover the internal barrier structures 62. The longitudinal position ofthe adhesive 180 and thus the longitudinal position of the elasticstrands 66 can thereby be controlled independently of the longitudinalposition of the internal barrier structures 62. In a particularlydesirably embodiment, the elastic strands 66 are attached to the casinglayers 65 so that the effective ends of the strands are located fromabout 1 to about 5 cm longitudinally outward of each end 69 of the sidebarrier structures 62. Alternatively, the elastic strands 66 may beattached to the casing layers 65 over the full length of theundergarment 20.

The method shown in FIG. 4 of making an undergarment is particularlydesirable because all of the component webs are continuously supplied tothe assembly process. Advantageously, this eliminates the need toseparately cut, place and register an individual component of theelasticized bumpers 60. Additionally, the length of the internal barrierstructures 62 is mechanically associated with the length of theabsorbent structure 42. Also, the ends 69 of the internal barrierstructures 62 are conveniently contained beneath the elasticized covers64. Further, the method allows the longitudinal and transverse positionof the elastic strands 66 to be controlled independently of the positionof the internal barrier structures 62.

An alternative embodiment of the invention is illustrated by anundergarment 200 shown in FIGS. 5 and 6. Components similar to thosepreviously described have been given the same reference numeral. Theundergarment 200 includes an elasticized bumper 202 disposed on eachside margin 38 of the undergarment. The elasticized bumpers 202desirably extend in the longitudinal direction 22 at least as far as theends 45 of the absorbent structures 42, and may extend beyond the ends45 up to and including to the end edges 26 and 27 of the undergarment200.

Each elasticized bumper 202 includes an internal barrier structure 62and an elasticized cover 64. The cover 64 fully encircles the internalbarrier structure 62 in the transverse direction 24, as illustrated inFIG. 6. The side edges 71 of the cover 64 overlap one another and arebonded together using adhesives, ultrasonic bonds, thermal bonds,mechanical bonds or other suitable means. The longitudinal ends 70 ofthe cover 64 may be coextensive with the ends 69 of the internal barrierstructure 62, and the ends 70 and 69 may be crimped and bonded togetherby adhesives or other suitable means.

Each cover 64 is operatively joined to one of the side margins 38 by abead 204 of adhesive. The adhesive bead 204 desirably is of sufficientsize to penetrate through the bodyside liner 44 and is continuous alongthe length of the elasticized bumper 202 so that liquid cannot penetratebetween the bumper and the moisture barrier 40. The covers 64 mayalternatively be bonded to the side margins 38 by ultrasonic bonds,thermal bonds, mechanical bonds or other suitable means.

The illustrated cover 64 includes a pair of casing layers 65 and aplurality of elastic strands 66 positioned between and operativelyjoined to the casing layers. In one particular embodiment, the cover 64includes at least 4 generally parallel elastic strands spaced generallyevenly between the side edges 71 of the cover. More desirably, though,the cover 64 includes at least 6 elastic strands 66, such as the 7strands shown in FIG. 6. The elastic strands 66 are desirably spacedfrom neighboring strands by less than about 8 mm, and particularly byfrom about 3 to about 6 mm from neighboring strands for improvedperformance.

The individual elastic strands 66 may be identical to one another.Alternatively, however, at least one of the elastic strands 66 hasgreater elastic power than at least one of the other elastic strands 66.Further, the elastic strands 66 having greater elastic power aredesirably located furthest from the point at which the elasticizedbumper 202 is bonded to the side margin 38. In the illustratedembodiment, for example, the cover 64 includes 7 elastic strands 66, and3 of those strands desirably have greater elastic power than theremaining 4 strands. The 3 strands of greater elastic power aredesirably located furthest from the adhesive bead 204. Advantageously,this configuration tends to form the undergarment 200 into a "U" shape.Again by way of illustration, a cover 64 may incorporate one set ofelastic strands 66 having a decitex of 620 and another set of elasticstrands having a decitex of 940. Both sets of strands may be stretchedto 270 percent elongation and bonded to the casing layer 65. The set of940 decitex strands could be positioned on the top portion of theelasticized bumper 202 and the set of 620 decitex strands could bepositioned on the side and bottom portions of the bumper.

The elasticized bumpers 202 function to contact the body of the wearerand inhibit lateral movement of liquid. In one embodiment, either thecovers 64 or the internal barrier structures 62 comprise a hydrophobicmaterial to inhibit the movement of liquid toward the side edges 28 and29 of the undergarment 200. To improve conformance to the body of thewearer, the elasticized bumpers 202 desirably possess the height andtension characteristics described above in relation to the elasticizedbumpers 60 shown in FIGS. 1-3.

In particularly desirable embodiments, the cover 64 is wrapped about theinternal barrier structure 62 but is not bonded to the internal barrierstructure. By leaving the cover 64 unadhered to the internal barrierstructure 62, the inner surface of the cover is free to slide over theexterior surface of the internal barrier structure, a feature whichtends to minimize the formation of large rugosities along the length ofthe elasticized bumper 202.

Test Methods

A suitable technique for determining the side margin tension value of anabsorbent article is the following Product Tension Test, whichdetermines the tension of the side margins of the undergarment 20 at apredetermined amount of stretch. The side margins of the undergarment 20include the elasticized bumpers 60 and 202. The Product Tension Testuses the following equipment and materials:

1. A lightbox mounted in a vertical position with clamps along the topedge.

2. A double clamp weight weighing 1000±5 grams.

3. A template 300 with a centerline reference 302, as illustrated inFIG. 7. The template has a length of 64.4 cm. Along each side of thetemplate, a pair of apertures 304 are centered along the length of thetemplate. The apertures in each pair are separated so that pen marks ona product made through the apertures are separated by 25.4 cm. Thisdistance may need to be modified, for example to 17.78 cm when smallerproducts such as diapers or training pants are tested. The apertures arespaced from the centerline reference a sufficient distance so that themarks correspond to the lateral location of the elastic strands 66.

4. An elastic tension tester such as a Chatillon DFG2 force gaugeavailable from John Chatillon & Sons Inc. located in New York, N.Y.,USA. The force gauge has upper and lower clamps, such as 3 inch Bulldogclamps.

5. An aluminum gage rod measuring 20.3 cm (8 inches) long. The lengthmay be adjusted to 16 cm for smaller products as noted above.

6. Pen with black ink.

7. Weights for calibration, 50, 100, 200, 500 grams, traceable to theNational Bureau of Standards (NBS).

8. Scissors

9. Ruler

A garment should be tested no sooner than 4 hours after it is produced.The garment to be tested is conditioned in a standard-conditionatmosphere of 23±1° C. (73.4±1.8° F.) temperature and 50±2% relativehumidity for 4 hours. The equipment is set up in the following manner:

1. Turn on the Chatillon force gauge and allow 10 minutes for the unitto warm-up.

2. Calibrate the Chatillon force gauge using the calibration weightsaccording to the manufacturer's instructions.

3. While supporting the force gage assembly, loosen the locking knob onthe back of the force gage assembly. Position the force gage assembly togive approximately 20.3 cm (16 cm for smaller products) of space betweenthe upper and lower clamps. Retighten the locking knob to hold the forcegage assembly in place.

4. Hold the gage rod between the upper and lower clamps. Use the fineadjustment knob located above the force gage to adjust the distanceuntil both clamps just touch the rod.

5. Verify that the units of measure on the force gage is set tokilograms. If required, push the "zero" button to zero the display.

The test specimens are prepared in the following manner. The garment iscentered beneath the lightbox clamps and hung with the moisture barrier40 against the lightbox. If possible, the clamps are attached to avoidthe absorbent structure 42 of the garment. The double clamp weight isattached to the lower end of the garment and gently lowered. Next, thetemplate is centered on the garment and each elasticized bumper 60 or202 is marked with the pen through the apertures. The procedure isrepeated until a total of 5 garments are marked. Each garment has twoleg cuff regions so there are a total of 10 test specimens.

Each of the 10 test specimens can then be tested by the followingprocedure.

1. Cut the side margins from each garment while it is hanging. Use thescissors to make a crosswise cut to the absorbent batt about 1/2 inch(13 mm) beyond the black ink mark. Cut lengthwise between theelasticized bumper and the absorbent batt extending to 1/2 inch (13 mm)beyond the black ink mark on the other end of the elasticized bumper.Then make a crosswise cut to free the elasticized bumpers from thegarment. If the absorbent batt must be cut to remove the elasticizedbumpers, the absorbent batt should be cut to remove as much absorbentmaterial from the test specimen as possible.

2. Wait 30 minutes but no more than 60 minutes from the time of cuttingbefore testing the specimen.

3. Place one end of the specimen into the upper clamp so the black linecoincides with the leading edge of the clamp. Take care so a foldover inthe liner does not get trapped in the clamp, as this may giveerroneously high results.

4. Press the "ZERO" button to tare the weight of the specimen.

5. Unhook the lower slider, raise it up, and place the bottom of thespecimen in the lower clamp so the marked line coincides with theleading edge of the clamp. The small reading showing on the displayshould have no effect on the final value.

6. Gently, lower the "Sample" sleeve over a three second time intervaluntil it touches and latches to the bottom latch.

7. Wait 5 seconds, then check the alignment of the black lines with theclamps. If no slippage has occurred, record the reading on the forcegauge. If slippage has occurred, replace the clamps as needed and test anew specimen.

The side margin tension is the average of the 10 measured values.

The foregoing detailed description has been for the purpose ofillustration. Thus, a number of modifications and changes may be madewithout departing from the spirit and scope of the present invention.For instance, alternative or optional features described as part of oneembodiment can be used to yield another embodiment. Additionally, twonamed components could represent portions of the same structure.Therefore, the invention should not be limited by the specificembodiments described, but only by the claims.

We claim:
 1. An absorbent article, comprising:a moisture barrier having longitudinal end edges and longitudinal side edges extending between the end edges; a bodyside liner bonded to the moisture barrier; an absorbent structure disposed between the bodyside liner and moisture barrier, at least one of the bodyside liner and moisture barrier forming opposite margins which extend beyond the absorbent structure; and an elasticized bumper disposed in each of the margins, each of the elasticized bumpers comprising:an internal barrier structure formed of a resilient material bonded to one of the margins; and an elasticized cover disposed over the internal barrier structure and bonded to one of the margins, the elasticized cover comprising a plurality of generally parallel elastic strands with at least one of the elastic strands having greater elastic power than at least one other elastic strand.
 2. The absorbent article of claim 1, wherein at least one of the internal barrier structures and the elasticized covers are liquid impermeable.
 3. The absorbent article of claim 1, wherein the elastic strands are spaced from neighboring strands by from about 3 to about 6 millimeters.
 4. The absorbent article of claim 1, wherein the at least one elastic strand with greater elastic power is positioned on top of the interior barrier structure.
 5. The absorbent article of claim 1, wherein the cover comprises a pair of casing layers and at least 4 elastic strands positioned between and operatively joined to the casing layers.
 6. The absorbent article of claim 1, wherein the elasticized bumpers have a height dimension of from about 3 to about 25 millimeters.
 7. The absorbent article of claim 1, wherein the internal barrier structures comprise a sliver structure formed of hydrophobic fibers.
 8. The absorbent article of claim 1, wherein the covers include opposite lateral portions and a central portion positioned between and interconnecting the lateral portions, the lateral portions being bonded to one of the margins and the central portions being unadhered to the internal barrier structures.
 9. The absorbent article of claim 1, wherein the elasticized bumpers are disposed in side margins of the article and the side margins possess a side margin tension of from about 0.06 to about 0.30 kilogram.
 10. An absorbent article, comprising:a moisture barrier having longitudinal end edges and longitudinal side edges extending between the end edges; a bodyside liner bonded to the moisture barrier; an absorbent structure disposed between the bodyside liner and moisture barrier, at least one of the bodyside liner and moisture barrier forming opposite margins which extend beyond the absorbent structure; and an elasticized bumper disposed in each of the margins, each of the elasticized bumpers comprising:an internal barrier structure bonded to one of the margins; and an elasticized cover disposed over the internal barrier structure and having lateral portions bonded to one of the margins, the elasticized cover being unadhered to the internal barrier structure.
 11. The absorbent article of claim 10, wherein the cover comprises a hydrophobic material.
 12. The absorbent article of claim 10, wherein the cover comprises a plurality of generally parallel elastic strands.
 13. The absorbent article of claim 12, wherein at least one of the elastic strands has greater elastic power than at least one other elastic strand.
 14. The absorbent article of claim 13, wherein the at least one elastic strand with greater elastic power is positioned on top of the interior barrier structure.
 15. The absorbent article of claim 10, wherein the cover comprises a pair of casing layers and at least 4 elastic strands positioned between and operatively joined to the casing layers.
 16. The absorbent article of claim 10, wherein the elasticized bumpers have a height dimension of from about 3 to about 25 millimeters.
 17. The absorbent article of claim 10, wherein the covers include opposite lateral portions and a central portion positioned between and interconnecting the lateral portions, the lateral portions being bonded to one of the margins and the central portions being unadhered to the internal barrier structures. 